Drill bit



July 28, 1931. A. E. CARLSON I 1,816,568

DRILL BIT Filed June 5, 1929 2 Sheets-Sheet l July 28, 1931. CARLSQN1,816,568

DRILL BIT I Filed June 5, 1929 2 Sheets-Sheet 2 Patented July 28, 193iUNITED STATES PATENT OFFICE,

ANTHONY E. CARLSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR, BY DIRECT ANDIESNE ASSIGNMEIITS, TO REED ROLLER BIT COMPANY, OF HOUSTON, TEXAS, A

CORPORATION OF TEXAS DRILL BIT Application filed-June 5, 1929. SerialNo. 368,483.

the rotary system of well drilling. In this industry a well is sunk bymeans of a drill bit secured to the lower end of a 5 drill pipe. Thedrill pipe extends upwardly through the well and is rotated by a rotarytable situated on the floor of a derrick of the well. The rotation ofthe drill bit cuts away the bottom of the hole and sinks the well.During the drilling of the well all of the exposed parts of the drillbit are subject to great wear which necessitates fre quent replacementthereof. It is an object of my invention to provide a protective memberfor a drill bit which fits thereover so as to protect the main body ofthe drill bit against wear, and which is removable so that, when worn,it may be D11;eplaced without replacing the entire drill In the drillingof a well, the sides thereof frequently cave in and bury the drill bitthus making it diflicult to withdraw the drill bit from the well. Y

5 It is another object of my invention to provide a drill bit havingcutting members My invention relates to drill bits used in on the uppersides thereof so that it may be I more readily withdrawn from the wellin casethe sides thereof cave in.

I In a drill bit in which the cutting members extend outwardly beyondthe body thereof, the edges of the cutting members frequently contactthe sides of the well and the joints in the well casing and make it idifficult to lower the drill bit into the well.

It is a further object of my invention to provide a drill in which aguiding member thereon extends'outwardly beyond the cutting members. Inthe drill bit of my invention, I prefer to secure this object by providing cutter carrying arms having, projections which extend outwardlybeyond the cutters of the drill.

Another object of my invention is to provide a bit in which the cuttersmay be readil installed or removed, and when installe are held in placeby strong means so that there is no danger of losing them.

A still further object of my invention is to provide a bit in which thepins or shafts Fig. 1 is a view showing the elements "of a my drill inthe manner of their assembly.

Fig. 2' is a View showing the appearance when assembled;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is a sectional view of my device as indicated by the line 44 ofFig. 3.

Fig. 5 is a sectional view of my device as indicated by the line 5--5 ofFig. 3.

Fig. 6 is a bottom view of my device as indicated by the arrow 6 of Fig.4.

Fig. 7 is a sectional view taken on the line 7-7 of Fig. 4.

As bestshown in Figs. 1, 3 and 4, a drill bit of my invention consistsof a drill body 11 having a central cylindrical portion 12 above whichis a threaded pin 13 adapted to be received into a tool box on a drillpipe. Between the cylindrical portion 12 and the pin 18 is a shoulder 14which permits tightening of the drill body 11 against the tool box.Below the cylindrical portion 12 is an annular flange 16 which is cutaway on two sides to form flattened sides 17. Below the flange 16 is adepending wall 18 which is axially displaced and has outwardly inclinededges 19.

The cylindrical. portion 12 of *the drill body is adapted to be receivedinto a cylindrical bore 20 in a tubular protective member 21. The flange16 is adapted to contact walls of an annular bore 22 in the protectivemember 21 and the flattened sides 17 of the flange 16 are adapted tocontact walls of a. shoulder on the bore 22. The protective member 21secured to the body 11 by 4 screws 24 which extend through openings inthe rotective member 21 and through a c lindrlcal slot 25 formed in thesurface of the cylindrical portion 12 of the body 11. The heads of thescrews 24 are retained in recesses 26 in the outer surface of theprotective member 21.

Fi s. 1 to 4 best show the construction of tie protective member 21which is tapered on the upper, exterior portion thereof to-form aconical wall on whlch are formed toothed projections 27. Formed on .thelower portion of the protective member 21 are diametrically-oppositedepending legs 28 and at right angles thereto are depending legs 29, thedepen ing legs 28 having vertica inner walls 30 and parallel-wallednotches 31 in the lower edges thereof, and the depending legs 29 havinginclined inner walls 33 and flat-walled notches 34 in the lower edgeswhich provide horizontal upper faces 35. In the outer surface of therotective member 21 between the depending egs 28 and 29 are cylindricalgrooves or flutes 36.

As best shown in Figs. 3, 4 and 6, a cylindrical cutter carrying arm 38is carried in a horizontal opening formed in the wall 18,the-parallel-sided ends 39 thereof being adapted to be received into thenotches 31 in the depending legs 28. On the cutter carrying arm 38 arerotatably supported horizontal cutters 40 having circumferential cuttingteeth, one of the cutters 40 having teethwhich extend in the axis A-A ofrotation of the drill bit. 41 are positioned between the cutters 40 andthe ,depending legs 28, the wear plates having central holes withparallel walls, and are adapted to be received onto the ends 39 of thecutter carrying arm 38 so as to prevent rotation thereof. Positionedbetween the cutters 40 and the depending wall 18 are wear plates 42. Ain 43 passes through the wear plates 42 an an opening in the dependingwall 18 and prevents rotation of the wear plates 42.

As best shown in Figs. 1, 4 and 7, circular recesses 45 having parallelside walls are formed in the edges 19 of the wall 18. The recesses 45are adapted to receive parallelsided ends 46 of cylindrical cuttercarrying arms 47 which are su ported therebyat right angles to theinclined edges 19 of the depending wall 18. The upper ends 48 of thecutter supporting arms 47 have parallel side walls which are adapted tobe received into the notches 34. 'The cutter carrying arms 47 areprevented from becoming detached from the wall 18 by horizontal upperwalls on the ends 48 which are adapted to contact the horizontal faces35 in the notches 34.

Rotatably supported on the inclined cutter carrying arms 47 are inclinedcutters 50 Wear plates" which are positioned between the inclined edges19 of the depending wall 18 and the inclined inner wall 33 of thedepending legs 29. These inclined cutters 50 are provided withcircumferential teeth, a portion of which is caused to project outwardlybeyond the outer surface of the protective member 21 by the inclinationof the cutters 50. I pre fer to construct my device so that the roundedends 48 of the arms 47 extend outwardly beyond the cutters 50 and formguiding members for the drill bit. Wear plates 51 are positioned betweenthe inclined cutters 50 and inclined edges 19 of the depending wall 18,and wear plates 52 are positioned between the cutters 50 and thelnclined inner wall 33. The wear plates 51 and 52 have central openingswith parallel side-walls which are adapted to be received onto the ends46 and 48 of the cutter carrying arms 47 in a manner to prevent relativerotation therebetween.

Opening from the top of the pin 13 is a central bore 53 which isconnected with the space below the flange 16 by four fluid each other. v

In the operation of my drill bit, the drill body 11 is rotated by meansof its connection with the drill pipe. rotates the protective member 21by means of the engagement of the flat faces 17 with the shoulders inthe bore 22 and by the engagement of the screws 24 with the sides of thecylindrical slot 25. The engagement of the cutters 40 and 50 with thebottom of the hole causes them to rotate. and cut away the bottom of thehole so as to sink the well. Rotary mud is supplied from the center ofthe drill pipe, through the bore 53 in the drill body 1 1, and throughthe fluid passages 54 to the space below the flange 16, where it picksup the cuttings and carries them upwardly through the flutes 36 in theprotective member 21.

As the protective member 21 encloses the drill body 11, the drill body11 is protected thereby from contact with the sides of the hole and fromwear occasioned thereby.

When the protective member 21 is worn sufficiently to requirereplacement, it may be easily removed by removing the screws 24 andwlthdrawing the protective member 21,

upwardly. New protective members and new cutters may be used to replacethe Worn parts and thus practically a new drill bit is secured withoutthe necessity of replacing the entire drill body.

In case the walls of the well cave in so as. to bury the drill bit, thetoothed projections 27 on the protective member 21 provide means forcutting away the fallen material so as to more readily withdraw thedrill bit from the well.

When inserting the drill bit into the well The drill body 11' e0openings 54 positioned at right angles to the cutting teeth on thecutters 50 which extend beyond the outer wall of the protective member21 are prevented from contacting the sides of the wall and the joints inthe well casing by the ends 48 of the cutter carrying arms 47 whichextend outwardly beyond the teeth on the cutters 50. The rounded ends 48contact the walls of the well and form guiding members for the drillbit.

It should be noted that a drill bit of my invention is particularlyadapted to drill various sizes of holes without changing the size of thedrill body 11. By making the cutters 50 and the protective member 21larger or smaller, my drill bit may be adapted to drill larger orsmaller holes.

My invention may be applicable to other forms of drill bits than thatdescribed herein without departing from the broad spirit of myinvention.

I claim as my invention:

1. In a drill bit, the combination of: a drill body having an upper endfor connection to a drill stem; a removable protective member extendingdownwardly to the lowermost portion of and surrounding said drill body;means for preventing relative movement between said drill body and saidprotective member; and a cutter secured to said drill body.

2. In a drill bit, the combination of: a drill body having an upper endfor connection to a drill stem; a removable protective member rigidlysecured to said drill body; a cutter carrying arm supported by thelowermost portion of said drill body and engaged by the lowermostportion of said protective member; and a cutter rotatably carried bysaid cutter carrying arm.

3. In a drill bit, the combination of: a drill body having an upper endfor connection to a drill stem; a protective member removably secured tosaid drill body in fixed relationship thereto, extending to thelowermost portion thereof, and having a toothed and tapered upper end;and a cutter secured to said drill body.

4. In a drill .bit, the combination of: a drill body having an upper endfor connection to a drill stem; a protective member removably secured tosaid drill body in fixed relationship thereto and having a toothed and,tapered upper end; a cutter carrying arm supported by the lowermostportion of said drill body and engaged by said protective member; and acutter rotatably carried by said cutter carrying arm.

5. In a drill bit, the combination of: a drill body having an upper endfor connection to a drill stem; a protective member removably secured tosaid drill body in fixed relationship thereto; a depending leg on saidprotective member; a cutter carrying arm supported by the lowermostportion of said drill body and engaged by said deoend-' ing leg; and acutter rotatably carried by said cutter carrying arm.

6. In a drill bit, a drill body having an upper end for connection to adrill stem,

tective member removably mounted on and surrounding said body andextending downwardly from said up er end, the lowermost portion of saidmember being slotted for the reception of said arms, and the surface ofthe upperportion of said member being faced upwardly and toothed.

8. In a drill bit, a drill body having a threaded pin for connection toa drill stem cutter arms on the lowermost portion of said body, cutterson said arms, and a protective member removably mounted on andsurrounding said body, the upper end of said member being substantiallyin the same plane with the lower end of said pin, said member extendingdownwardly and having a slotted lower end for the reception of saidarms, the surface of the upper portion of said member being facedupwardly and toothed.

9. In a drill bit, a drill bodyhaving a threaded pin on its upperend forconnection to a drill stem, cutter arms on the lowermost portion of saidbody, said arms being substantially at a right angle to each other,cutters on said arms, and a protective member removably mounted on andsurrounding said body, the upper end of said member being adjacent thelower end of said pin, and the-lower end of said body being slotted forthe reception of said arms.

10. In a drill bit, a drill body having a threaded pin on its upper end,and a pair of cutter arms on and inclined upwardly and outwardlyfromvopposite sides of the lowermost portion of said body, another armon and at substantially a right angle to the axis of said body and tothe plane of said inclined arms, cutters on said arms, and a protectivemember removably mounted on and surrounding said body, the upper end ofsaid body being adjacent the lower end of said pin, and the lower end ofsaid body being slotted for the reception of said arms.

Intestimony whereof, I have hereunto set my hand at Los Angeles,California, 7 this 29th day of May, 1929.

ANTHONY E. CARLSON.

